tests/Matrix.Tests.ps1
& (Join-Path $PSScriptRoot '_setup.ps1') 'classes' Describe 'Matrix class static methods' { It 'can create an NxN multi-dimensional array' { $N = 5 $Matrix = [MatrixTest]::New($N) $Matrix.Rows.Count | Should -Be $N $Matrix.Rows[0].Count | Should -Be $N } It 'can create an MxN multi-dimensional array' { $M = 8 $N = 6 $Matrix = [MatrixTest]::New($M,$N) $Matrix.Rows.Count | Should -Be $M $Matrix.Rows[0].Count | Should -Be $N } It 'can create unit matrices' { $Unit = [MatrixTest]::Unit(1) $Unit.Size | Should -Be 1,1 $Unit.Rows[0] | Should -Be 1 $Unit = [MatrixTest]::Unit(2) $Unit.Size | Should -Be 2,2 $Unit.Rows[0] | Should -Be 1,1 $Unit.Rows[1] | Should -Be 1,1 $Unit = [MatrixTest]::Unit(3) $Unit.Size | Should -Be 3,3 $Unit.Rows[0] | Should -Be 1,1,1 $Unit.Rows[1] | Should -Be 1,1,1 $Unit.Rows[2] | Should -Be 1,1,1 } It 'can create identity matrices' { $Identity = [MatrixTest]::Identity(2) $Identity.Size | Should -Be 2,2 $Identity.Rows[0] | Should -Be 1,0 $Identity.Rows[1] | Should -Be 0,1 $Identity = [MatrixTest]::Identity(4) $Identity.Size | Should -Be 4,4 $Identity.Rows[0] | Should -Be 1,0,0,0 $Identity.Rows[1] | Should -Be 0,1,0,0 $Identity.Rows[2] | Should -Be 0,0,1,0 $Identity.Rows[3] | Should -Be 0,0,0,1 } It 'can transpose matrices' { $Matrix = [MatrixTest]::New(3) $Matrix.Rows[0][0] = 1 $Matrix.Rows[0][1] = 2 $Matrix.Rows[0][2] = 3 $Matrix.Rows[1][0] = 4 $Matrix.Rows[1][1] = 5 $Matrix.Rows[1][2] = 6 $Matrix.Rows[2][0] = 7 $Matrix.Rows[2][1] = 8 $Matrix.Rows[2][2] = 9 $Matrix.Rows[0] | Should -Be 1,2,3 $Matrix.Rows[1] | Should -Be 4,5,6 $Matrix.Rows[2] | Should -Be 7,8,9 $Transposed = [MatrixTest]::Transpose($Matrix) $Transposed.Rows[0] | Should -Be 1,4,7 $Transposed.Rows[1] | Should -Be 2,5,8 $Transposed.Rows[2] | Should -Be 3,6,9 $Original = [MatrixTest]::Transpose($Transposed) $Original.Rows[0] | Should -Be 1,2,3 $Original.Rows[1] | Should -Be 4,5,6 $Original.Rows[2] | Should -Be 7,8,9 } It 'can add two or more Matrices' { $A = [MatrixTest]::Identity(2) $Sum = [MatrixTest]::Add($A,$A) $Sum.Rows[0] | Should -Be 2,0 $Sum.Rows[1] | Should -Be 0,2 $Sum = [MatrixTest]::Add($A,$A,$A) $Sum.Rows[0] | Should -Be 3,0 $Sum.Rows[1] | Should -Be 0,3 } It 'can calculate the determinant for 2x2 matrices' { [MatrixTest]::Det([MatrixTest]::Unit(2)) | Should -Be 0 [MatrixTest]::Det([MatrixTest]::Identity(2)) | Should -Be 1 $A = [MatrixTest]::New(2) $A.Rows[0][0] = 1 $A.Rows[0][1] = 2 $A.Rows[1][0] = 3 $A.Rows[1][1] = 4 [MatrixTest]::Det($A) | Should -Be -2 } It 'can calculate the determinant for 3x3 matrices' { [MatrixTest]::Det([MatrixTest]::Unit(3)) | Should -Be 0 [MatrixTest]::Det([MatrixTest]::Identity(3)) | Should -Be 1 $A = [MatrixTest]::New(3) $A.Rows[0][0] = 2 $A.Rows[0][1] = 3 $A.Rows[0][2] = -4 $A.Rows[1][0] = 0 $A.Rows[1][1] = -4 $A.Rows[1][2] = 2 $A.Rows[2][0] = 1 $A.Rows[2][1] = -1 $A.Rows[2][2] = 5 [MatrixTest]::Det($A) | Should -Be -46 $A = [MatrixTest]::New(3) $A.Rows[0][0] = 1 $A.Rows[0][1] = 2 $A.Rows[0][2] = 3 $A.Rows[1][0] = 4 $A.Rows[1][1] = -2 $A.Rows[1][2] = 3 $A.Rows[2][0] = 2 $A.Rows[2][1] = 5 $A.Rows[2][2] = -1 [MatrixTest]::Det($A) | Should -Be 79 } It 'can calculate the determinant for 4x4 matrices' { [MatrixTest]::Det([MatrixTest]::Unit(4)) | Should -Be 0 [MatrixTest]::Det([MatrixTest]::Identity(4)) | Should -Be 1 $A = [MatrixTest]::New(4) $A.Rows[0][0] = 3 $A.Rows[0][1] = -2 $A.Rows[0][2] = -5 $A.Rows[0][3] = 4 $A.Rows[1][0] = -5 $A.Rows[1][1] = 2 $A.Rows[1][2] = 8 $A.Rows[1][3] = -5 $A.Rows[2][0] = -2 $A.Rows[2][1] = 4 $A.Rows[2][2] = 7 $A.Rows[2][3] = -3 $A.Rows[3][0] = 2 $A.Rows[3][1] = -3 $A.Rows[3][2] = -5 $A.Rows[3][3] = 8 [MatrixTest]::Det($A) | Should -Be -54 $A = [MatrixTest]::New(4) $A.Rows[0][0] = 5 $A.Rows[0][1] = 4 $A.Rows[0][2] = 2 $A.Rows[0][3] = 1 $A.Rows[1][0] = 2 $A.Rows[1][1] = 3 $A.Rows[1][2] = 1 $A.Rows[1][3] = -2 $A.Rows[2][0] = -5 $A.Rows[2][1] = -7 $A.Rows[2][2] = -3 $A.Rows[2][3] = 9 $A.Rows[3][0] = 1 $A.Rows[3][1] = -2 $A.Rows[3][2] = -1 $A.Rows[3][3] = 4 [MatrixTest]::Det($A) | Should -Be 38 } It 'can calculate the determinant for matrices larger than 4x4' { [MatrixTest]::Det([MatrixTest]::Unit(10)) | Should -Be 0 [MatrixTest]::Det([MatrixTest]::Identity(10)) | Should -Be 1 $A = [MatrixTest]::New(6) $A.Rows[0][0] = 12 $A.Rows[0][1] = 22 $A.Rows[0][2] = 14 $A.Rows[0][3] = 17 $A.Rows[0][4] = 20 $A.Rows[0][5] = 10 $A.Rows[1][0] = 16 $A.Rows[1][1] = -4 $A.Rows[1][2] = 7 $A.Rows[1][3] = 1 $A.Rows[1][4] = -2 $A.Rows[1][5] = 15 $A.Rows[2][0] = 10 $A.Rows[2][1] = -3 $A.Rows[2][2] = -2 $A.Rows[2][3] = 3 $A.Rows[2][4] = -2 $A.Rows[2][5] = 8 $A.Rows[3][0] = 7 $A.Rows[3][1] = 12 $A.Rows[3][2] = 8 $A.Rows[3][3] = 9 $A.Rows[3][4] = 11 $A.Rows[3][5] = 6 $A.Rows[4][0] = 11 $A.Rows[4][1] = 2 $A.Rows[4][2] = 4 $A.Rows[4][3] = -8 $A.Rows[4][4] = 1 $A.Rows[4][5] = 9 $A.Rows[5][0] = 24 $A.Rows[5][1] = 6 $A.Rows[5][2] = 6 $A.Rows[5][3] = 3 $A.Rows[5][4] = 4 $A.Rows[5][5] = 22 [MatrixTest]::Det($A) | Should -Be 12228 } It 'can produce the dot product of two matrices' { $Identity = [MatrixTest]::Identity(2) $A = $Identity.Clone() $A.Rows[1][1] = 0 $B = $Identity.Clone() $B.Rows[0][0] = 0 $Product = [MatrixTest]::Dot($A,$B) $Product.Size | Should -Be 2,2 $Product.Rows[0] | Should -Be 0,0 -Because 'the dot product of orthogonal matrices should be zero' $Product.Rows[1] | Should -Be 0,0 -Because 'the dot product of orthogonal matrices should be zero' $A.Rows[0][0] = 1 $A.Rows[0][1] = 2 $A.Rows[1][0] = 3 $A.Rows[1][1] = 4 $B.Rows[0][0] = 1 $B.Rows[0][1] = 1 $B.Rows[1][0] = 0 $B.Rows[1][1] = 2 $Product = [MatrixTest]::Dot($A,$B) $Product.Rows[0] | Should -Be 1,5 $Product.Rows[1] | Should -Be 3,11 $Product = [MatrixTest]::Dot($B,$A) $Product.Rows[0] | Should -Be 4,6 -Because 'the dot product is not commutative' $Product.Rows[1] | Should -Be 6,8 -Because 'the dot product is not commutative' $A = [MatrixTest]::New(1,2) $A.Rows[0][0] = 2 $A.Rows[0][1] = 1 $B = [MatrixTest]::New(2,3) $B.Rows[0][0] = 1 $B.Rows[0][1] = -2 $B.Rows[0][2] = 0 $B.Rows[1][0] = 4 $B.Rows[1][1] = 5 $B.Rows[1][2] = -3 $Product = [MatrixTest]::Dot($A,$B) $Product.Size | Should -Be 1,3 -Because 'dot product supports matrices of different sizes' $Product.Rows[0] | Should -Be 6,1,-3 $A = [MatrixTest]::New(2) $A.Rows[0][0] = 2 $A.Rows[0][1] = 5 $A.Rows[1][0] = 1 $A.Rows[1][1] = 3 $B = [MatrixTest]::New(2) $B.Rows[0][0] = 3 $B.Rows[0][1] = -5 $B.Rows[1][0] = -1 $B.Rows[1][1] = 2 [MatrixTest]::Dot($A,$B) | Test-Equal $Identity | Should -BeTrue -Because '$A and $B are invertible' } } Describe 'Matrix class instance' { It 'provides iterator of index element index pairs' { $A = [MatrixTest]::New(3) $A.Indexes() | Should -HaveCount 9 } It 'can create clones' { $Matrix = [MatrixTest]::New(2) $Matrix.Rows[0][0] = 1 $Matrix.Rows[0][1] = 2 $Matrix.Rows[1][0] = 3 $Matrix.Rows[1][1] = 4 $Clone = $Matrix.Clone() $Clone.Rows[0] | Should -Be 1,2 $Clone.Rows[1] | Should -Be 3,4 } It 'can be multiplied by a scalar constant' { $A = [MatrixTest]::Identity(2) [MatrixTest]::Add($A,$A,$A) | Test-Equal $A.Multiply(3) | Should -BeTrue $Product = $A.Multiply(7) $Product.Rows[0] | Should -Be 7,0 $Product.Rows[1] | Should -Be 0,7 } It 'can remove rows' { $A = [MatrixTest]::New(3) $A.Rows[0][0] = 1 $A.Rows[0][1] = 2 $A.Rows[0][2] = 3 $A.Rows[1][0] = 4 $A.Rows[1][1] = 5 $A.Rows[1][2] = 6 $A.Rows[2][0] = 7 $A.Rows[2][1] = 8 $A.Rows[2][2] = 9 $Edited = $A.RemoveRow(0) $Edited.Size | Should -Be 2,3 $Edited.Rows[0] | Should -Be 4,5,6 $Edited.Rows[1] | Should -Be 7,8,9 $Edited = $A.RemoveRow(1) $Edited.Size | Should -Be 2,3 $Edited.Rows[0] | Should -Be 1,2,3 $Edited.Rows[1] | Should -Be 7,8,9 $Edited = $A.RemoveRow(2) $Edited.Size | Should -Be 2,3 $Edited.Rows[0] | Should -Be 1,2,3 $Edited.Rows[1] | Should -Be 4,5,6 $Edited = $A.RemoveRow(2).RemoveColumn(0) } It 'can remove columns' { $A = [MatrixTest]::New(3) $A.Rows[0][0] = 1 $A.Rows[0][1] = 2 $A.Rows[0][2] = 3 $A.Rows[1][0] = 4 $A.Rows[1][1] = 5 $A.Rows[1][2] = 6 $A.Rows[2][0] = 7 $A.Rows[2][1] = 8 $A.Rows[2][2] = 9 $Edited = $A.RemoveColumn(0) $Edited.Size | Should -Be 3,2 $Edited.Rows[0] | Should -Be 2,3 $Edited.Rows[1] | Should -Be 5,6 $Edited.Rows[2] | Should -Be 8,9 $Edited = $A.RemoveColumn(1) $Edited.Size | Should -Be 3,2 $Edited.Rows[0] | Should -Be 1,3 $Edited.Rows[1] | Should -Be 4,6 $Edited.Rows[2] | Should -Be 7,9 $Edited = $A.RemoveColumn(2) $Edited.Size | Should -Be 3,2 $Edited.Rows[0] | Should -Be 1,2 $Edited.Rows[1] | Should -Be 4,5 $Edited.Rows[2] | Should -Be 7,8 $Edited = $A.RemoveColumn(0).RemoveRow(0) $Edited.Size | Should -Be 2,2 $Edited.Rows[0] | Should -Be 5,6 $Edited.Rows[1] | Should -Be 8,9 } It 'can be converted to string output' { $Matrix = [MatrixTest]::New(2) $Matrix.Rows[0][0] = 1 $Matrix.Rows[0][1] = 2 $Matrix.Rows[1][0] = 3 $Matrix.Rows[1][1] = 4 $Matrix.ToString() | ConvertTo-Json | Should -Be '"1,2\r\n3,4"' [MatrixTest]::Unit(3).ToString() | ConvertTo-Json | Should -Be '"1,1,1\r\n1,1,1\r\n1,1,1"' } } |